Evolution of strain state of a rolled aluminum sheet in multi-pass conventional spinning

2020 ◽  
pp. 1-25
Author(s):  
Shiori Gondo ◽  
Hirohiko Arai ◽  
Satoshi Kajino ◽  
Shizuka Nakano
Keyword(s):  
Strain State ◽  
Radial Direction ◽  
Aluminum Sheet ◽  
Movement Direction ◽  
Forming Force ◽  
State Evolution ◽  
Rolled Aluminum ◽  
Conventional Spinning ◽  
Cylindrical Cup ◽  
The Relationship

Abstract This study clarified the strain state evolution of a cylindrical cup spun from a rolled aluminum sheet in 13 passes. Measurements of radial (εr), circumferential (εθ), and thickness (εt) directional strains as well as forming forces revealed that the strain state evolved as follows: the cup-wall exhibits εr < 0 and small |εθ| and |εt| in early passes and εr > 0, εθ < 0, and εt < 0 in later passes; meanwhile, the cup-edge exhibits εr > 0 and small |εθ| and |εt| in early passes and εr > 0, εθ< 0, and εt > 0 in later passes. The relationship between the strain states and forming force is interpreted as follows. The normal-direction forming force, which pushes into the workpiece in the thickness direction, primarily deforms the workpieces. The radial-direction forming force, toward to the edge along the workpiece configuration, facilitates elongation in the radial direction of the cup-wall and results in εr > 0 during spinning. By contrast, a small radial-direction forming force or a forming force whose direction is inverse against the roller movement direction restrains to elongate the material in the radial direction and facilitates shrinkage, thereby resulting in εr < 0 in the cup-edge in early passes. Furthermore, the small or inverse directional force facilitates the accumulation of the material to the edge and results in εt > 0 in latter passes.

scholarly journals Texture Evolution of a Rolled Aluminum Sheet in Multi-Pass Conventional Spinning

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 793
Author(s):  
Shiori Gondo ◽  
Hirohiko Arai ◽  
Satoshi Kajino ◽  
Shizuka Nakano
Keyword(s):  
Electron Backscatter Diffraction ◽  
Layer Structure ◽  
Texture Evolution ◽  
Aluminum Sheet ◽  
Thickness Direction ◽  
Type Layer ◽  
Rolled Aluminum ◽  
Sandwich Type ◽  
Conventional Spinning ◽  
Cylindrical Cup

This study clarified the evolution of texture in the thickness direction of the cylindrical cup which was spun from a rolled aluminum sheet in 13 passes, using electron backscatter diffraction pattern analysis. The study also obtained the relationship between the strain and layer structure, characterized by the textures. The spun workpiece had three layers in the thickness direction. The layer structure was composed of four types of textures: the Cu texture, “texture-I”, which rotated 20° around <111> from the Cu texture; “texture-II”, which rotated 5° around its <110> from the Cu texture; and “texture-III”, which rotated 10° around its <001> from texture-I. When a blank disk had the sandwich-type layer structure Cu-I-Cu in its thickness direction, the structure changed to the Cu-II-II and Cu-III-III layer structures for the negative and positive thickness directional strains, respectively. A complex-type structure was found in the transition from Cu-I-Cu to Cu-II-II and Cu-III-III.

Earing and Anisotropy Indices of Texture Components in the Hot-Rolled 3104 Alloy

2014 ◽  
Vol 698 ◽  
pp. 501-506 ◽  
Author(s):  
Evgeniy Aryshenskiy ◽  
Anna F. Grechnikova ◽  
Vasiliy V. Yashin
Keyword(s):  
Software Package ◽  
Rolled Sheet ◽  
X Ray ◽  
Finite Element Software ◽  
Anisotropy Index ◽  
Rolled Aluminum ◽  
Cylindrical Cup ◽  
Hot Rolled ◽  
The Relationship ◽  
Cup Drawing

The paper describes an experimental verification of a previously proposed formula establishing the relationship between the crystallographic parameters of a rolled sheet and the anisotropy index in a hot-rolled aluminum alloy. The main texture components were identified in the hot-rolled 3104 alloy using the X-ray structure analysis. The crystallographic parameters and anisotropy indices were then calculated both for the entire workpiece and for each individual texture component. The earing level of the hot-rolled workpiece was determined using the process of cylindrical cup drawing. Cup formation was also simulated using the finite element software package PAM STAMP. The earing data obtained through t simulation were compared with experimental results. For the validation of the calculations the hot-rolled workpiece anisotropy indices were also experimentally determined.

DIRECTIONAL DIFFUSION OF K ATOMS ON A GaAs(110) SURFACE

2006 ◽  
Vol 05 (06) ◽  
pp. 895-900 ◽  
Author(s):  
NOBUYUKI ISHIDA ◽  
AGUS SUBAGYO ◽  
KAZUHISA SUEOKA
Keyword(s):  
Dipole Moment ◽  
Electric Field ◽  
Radial Direction ◽  
Negative Sample ◽  
Directional Diffusion ◽  
Sample Bias ◽  
Induced Dipole ◽  
High K ◽  
Scanning Area ◽  
The Relationship

We performed STM measurements on the K/GaAs (110) surface with high K coverage. The K atoms gradually disappeared while scanning the tip over the surface at negative sample bias voltage. The phenomenon strongly occurred over the scanning area and can be explained by the field-induced surface diffusion from the scanning area to radial direction. Considering the interaction between the dipole moment of the adsorbed K atoms and the electric field, we discuss the relationship between the static and induced dipole moment of K atoms on a GaAs (110) surface.

Residual Stress Distribution through Thickness in Cold-Rolled Aluminum Sheet

2014 ◽  
Vol 622-623 ◽  
pp. 1000-1007 ◽  
Author(s):  
Nobuyuki Hattori ◽  
Ryo Matsumoto ◽  
Hiroshi Utsunomiya
Keyword(s):  
Residual Stress ◽  
Friction Coefficient ◽  
Stress Distribution ◽  
Aspect Ratio ◽  
Rolling Direction ◽  
Contact Length ◽  
Residual Stress Distribution ◽  
Aluminum Sheet ◽  
Rolled Aluminum ◽  
Cold Rolled

Distribution of residual stress through the thickness of a cold-rolled aluminum sheet is analyzed by the elastic-plastic finite element method under plane strain condition. Single-pass rolling of 2mm-thick aluminum sheet is considered. Influences of roll diameterD, reduction in thicknessr, and friction coefficientμare investigated. When the friction is low (μ= 0.1 and 0.2), and the case with smaller rolls (D= 130 mm) and low reduction (r= 5%), the residual stress in the rolling direction is compressive at surface and tensile around the layer quarter deep from the surface. While in the case with larger rolls (D= 310 mm) and high reduction (r= 30%), the stress is tensile at surface and the stress decreases to compressive with increasing depth from surface. In other words, with low friction, the residual stress distribution strongly depends on the aspect ratio (contact length / mean thickness) of the roll bite. On the other hand, when the friction coefficient is high (μ= 0.4), the residual stress is compressive at surface regardless of roll diameter and reduction. It means that the friction makes the residual stress at surface more compressive. It is found that the relationship between the residual stress at surface and the aspect ratio is almost linear, and that the slope depends on the friction coefficient.

scholarly journals Force parameters of metal deformation during sheet drawing

2020 ◽  
Vol 16 (6) ◽  
pp. 493-503
Author(s):  
Yury A. Morozov
Keyword(s):  
Stress State ◽  
Strain State ◽  
Sheet Material ◽  
Forming Force ◽  
High Quality ◽  
State Process ◽  
The Matrix ◽  
Metal Deformation ◽  
Volumetric Stress ◽  
Steady State Process

The aim of the work. The effect of the curvature of the rounding of torus surfaces during the formation of a cylindrical product (glass) is investigated, taking into account the plastic thinning of the deformable material at the end edges of the matrix and pressing punch. Methods. The existing scheme for determining the power parameters of sheet drawing is analyzed, based on the assumption of the implementation of some abstract stress state in the material; mainly conditional tensile strength. At the same time, the possibility of forming the product without destruction determines the obvious overestimation of the stress level. A mathematical model of the volumetric stress state of the metal is being developed, which makes it possible to assess the deformation and stress state during the formation of a cold-drawn product, i. e. the folding of the sheet blank along the end radius of the rounding of the pressing punch and the steady-state process of drawing the blank into the deformation zone with successive bending/straightening of the material along the edge of the matrix are considered. The level of radial stresses during folding and stretching of sheet material is estimated, taking into account its strain hardening and thinning, which determine the forming force. The obtained results will make it possible to simulate the stress-strain state of the metal during the development of sheet drawing technology: to establish the amount of thinning, to estimate the level of radial stresses in the formation of rounding of torus surfaces along the end edges of the matrix and the pressing punch, as well as to determine the power parameters of the formation, which will prevent the destruction of the pulled part, guaranteeing obtaining high-quality products and more accurately choosing the deforming equipment.

Effect of Anisotropy on Shear Wave Velocity in Wood

2012 ◽  
Vol 535-537 ◽  
pp. 1923-1926
Author(s):  
Jian Ping Zhou ◽  
Jin Xia Liu ◽  
Wen Yang Gao ◽  
Zhi Wen Cui ◽  
Wei Guo Lv ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Radial Direction ◽  
Rotation Angle ◽  
Wood Specimen ◽  
Shear Waves ◽  
Circular Ring ◽  
The Relationship ◽  
Intrinsic Birefringence

The velocities of shear waves propagating along radial direction of birch and elmwood specimens are measured in order to study the effect of anisotropy on shear wave velocity. The relationship between the shear wave velocity and the oscillation direction is examined by rotating an ultrasonic sensor. The results indicate that the effect of anisotropy on shear wave velocity in birch and elmwood specimens is similar to Japanese magnolia specimen. When the oscillation direction of the shear wave corresponds to the certain anisotropic direction of the wood specimen, the shear wave velocity decreases sharply and the relationship between shear wave velocity and rotation angle tends to become discontinuous. The intrinsic birefringence due to the anisotropy of birch and elmwood woods is observed. Their texture anisotropies are strong. In an isotropic nylon, on the contrary, the value of shear wave velocity was similar to a circular ring. This investigation is significant meanings in architectural and civil engineering field.

scholarly journals Evolution of the reinforced I-beam strain state

2018 ◽  
Vol 143 ◽  
pp. 01017 ◽  
Author(s):  
Artem Ustinov ◽  
Anatolij Klopotov ◽  
Aleksandr Potekaev ◽  
Vasilij Plevkov ◽  
Ekaterina Marchenko
Keyword(s):  
Composite Material ◽  
Strain State ◽  
Image Correlation ◽  
Correlation Technique ◽  
Digital Image Correlation Technique ◽  
Load Bearing Capacity ◽  
Four Point Bending ◽  
Reinforced Beams ◽  
State Evolution ◽  
Bending Loading

The paper presents experimental results of the strain state evolution of the steel I-beam reinforced with composite material under four-point bending loading. Digital image correlation technique was used to trace the evolution of plastic strain zones distribution. The images of longitudinal relative strain on the lateral surface of the reinforced I-beam web were obtained and analyzed. It was found that the increase of load-bearing capacity of the reinforced beams can exceed 26 %.

Strain state evolution and thickness-dependent properties of epitaxialNd0.7Sr0.3MnO3films

2007 ◽  
Vol 75 (21) ◽  
Author(s):  
S. W. Jin ◽  
G. Y. Gao ◽  
Z. Z. Yin ◽  
Z. Huang ◽  
X. Y. Zhou ◽  
...  
Keyword(s):  
Strain State ◽  
State Evolution

scholarly journals A NUMERICAL STUDY OF STRESS-STRAIN STATE EVOLUTION IN STRUCTURALLY INHOMOGENEOUS MATERIALS SUBJECTED TO UNIAXIAL LOADING

2016 ◽  
Vol 3 ◽  
pp. 175-187 ◽  
Author(s):  
Sergey Smirnov ◽  
Anatoly Konovalov ◽  
Marina Myasnikova ◽  
Yury Khalevitsky ◽  
Alexander Smirnov
Keyword(s):  
Strain State ◽  
Numerical Study ◽  
Uniaxial Loading ◽  
Inhomogeneous Materials ◽  
Stress Strain ◽  
Stress Strain State ◽  
State Evolution
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